Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => 350 Talk => Topic started by: dcr on June 19, 2017, 10:10:20 AM

Title: 350 Head Gaskets
Post by: dcr on June 19, 2017, 10:10:20 AM
Just noticed that both head gaskets are leaking out the front. They are the new copper type gaskets. When idling, I can clearly see oil oozing out of the front of both heads.

I removed both heads and cleaned up all the threads making sure each nut had free travel all the way down the bolts. I also verified that the nuts were not bottoming out on the bolt threads before snugging up - there is plenty of thread left once the nuts come in contact with the washers on the heads. I checked the head gaskets for burrs or imperfections and they both seem fine. I also checked the heads and cylinders for imperfections on the mating surfaces and found nothing. Gasket thickness seems to be a consistent .075 mm.

Any ideas or suggestions?

Dan
Title: Re: 350 Head Gaskets
Post by: OldSwartout on June 19, 2017, 11:01:29 AM
Just reuse the copper gaskets.  Heat them with a torch until red hot to anneal (soften) them, but not hot enough to melt.  Put a light coat of copper gasket cement on both sides.  I use the spray gasket sealer and lay them out on a paper towel and give them a light spray, flip them and spray the other side.  Put them and the heads back on and torque the nuts to 18-21 ft. lb.

Checking the heads to make certain they are reasonably flat first is a good idea. A good straightedge will work as a check, although rubbing the head on a sheet of 280-400 grit wet-or-dry paper on a sheet of glass or a nice flat workbench will tell you a lot, also, and you can use that to true them up if needed.
Title: Re: 350 Head Gaskets
Post by: dcr on June 20, 2017, 08:21:01 AM
Thanks Karl. I checked the heads with a straight edge and cant see any imperfections. I tried your head and gasket cement suggestion last night. Didn't have the opportunity to fire it up after getting it all back together but will kick it over tonight and hope for the best.

Dan
Title: Re: 350 Head Gaskets
Post by: dcr on June 21, 2017, 08:23:02 AM
Started on the first kick and no more head gasket leaks. Ran around the neighborhood last night and I'm sure my homeowners association is working on getting me out of there. Nothing like the loud crack of a 2 stroke ripping up the streets at 10 pm in a typically clam and quiet residential neighborhood.

Dan
Title: Re: 350 Head Gaskets
Post by: husker on June 21, 2017, 09:24:21 AM
May have to try your suggestion Karl as both of my head gaskets are leaking oil too.  Got another 1st place trophy in the import division at the Awesome Biker Nights in Sioux City, IA..........Rod
Title: Re: 350 Head Gaskets
Post by: slawsonb on June 21, 2017, 12:08:58 PM
The Husker just keeps rolling....Nice going, Rod.
...bert